According to some historians, the first snowshoes were developed about 6,000 years ago in Central Asia. Snowshoes have been used in North America for many centuries, first by native American peoples and later by trappers, explorers and other European settlers. Traditionally, snowshoes were formed from light oval or teardrop shaped wooden frames strung with thongs made from animal hide. The resulting snowshoe could then be strapped to a person's foot, i.e., directly or via footgear, so as to enable the person to walk in soft snow without sinking too deeply.
Today, snowshoes are most commonly used for recreation and by mountaineers to facilitate winter access to remote backcountry locations. Although the materials and production techniques have changed, modern snowshoes have much in common with traditional snowshoes developed over the centuries. FIG. 1 illustrates some features of one type of snowshoe 1 in common use today. The general shape of the snowshoe 1 is defined by a tubular perimeter structure 2 which is ordinarily formed from aluminum. The requisite flotation surface area is typically provided by webbing or a platform 3, formed from animal hide or synthetic materials, which is connected to the tubular perimeter structure 2 via sturdy lacing 4 or rivets. The snowshoe 1 is attached to the wearer's foot via footgear 5 using a toestrap 6, and an additional heel strap 7 is usually provided. Often, a hinged metal device or so-called crampon 8 which extends through an opening 9 in platform 3 is provided to improve forward traction on hills or ice.
Despite the long evolution of the snowshoe art, current snowshoes are subject to certain limitations. For example, when the snowshoer traverses a steep hill, current snowshoes are highly susceptible to side slippage. Similarly, current snowshoes can slip forwardly or rearwardly when a hill is addressed directly, particularly in icy conditions. In addition to being a source of annoyance, such slipping can be a matter of grave safety concern for the backcountry mountaineer. Conventional snowshoes do not always provide adequate protection against forward, rearward and side slippage.
Another limitation of current snowshoes is that the snowshoes have invariable flotation characteristics relating to the size of the snowshoe. However, the desired flotation characteristics of a snowshoe vary from user-to-user, from application-to-application, and depending on snow conditions or other factors. For example, a larger snowshoe is normally better for a heavier snowshoer, when carrying a heavy pack or when snowshoeing in deep and soft snow. Smaller snowshoes are typically preferred for running or racing (as is becoming increasingly popular). Many avid snowshoeing enthusiasts therefore have more than one pair of snowshoes.
This is not a completely satisfactory situation for a number of reasons. First, the expense of acquiring more than one pair of snowshoes is prohibitive for many. In addition, the snowshoer cannot always accurately predict what conditions may be encountered during an outing. Snow conditions can change rapidly, particularly in back-country mountaineering expeditions involving large altitude changes. Moreover, for outings lasting several days, conditions may change due to storms, wind, temperature changes and other weather phenomena. Furthermore, as can be readily appreciated, it is not always convenient to store and carry more than one pair of snowshoes.
Current snowshoes as described above are also subject to a certain instability relating to snow compaction. In particular, as the snowshoer places weight on the snowshoe, the platform tends to flex to a concave shape. As a result, snow may be forced towards the snowshoe perimeter rather than providing stable support under the snowshoer's foot.
Additionally, current snowshoes tend to create resistance to the shuffling movement entailed in forward snowshoeing. In this regard, the tubular perimeter and angled orientation of common snowshoe perimeter structures result in snow plowing when the snowshoe is shuffled in a forward direction. Moreover, current snowshoes generally do not facilitate forward tracking, i.e., even on flat ground, current snowshoes can easily drift transversely to the desired direction of travel during shuffling.
The snowshoe binding has also presented persistent challenges for snowshoe designers as many desired binding qualities seemingly demand incompatible design features. For example, the binding must be able to securely accommodate a variety of footgear sizes and styles in order to be suitable for general use. However, in order to facilitate proper snowshoeing motion and reduce strain on the snowshoer, the binding must provide excellent lateral foot stability, limit vertical movement of the snowshoer's footgear, and limit forward or rearward slipping of the footgear as may occur in hilly terrain. In addition, it is highly desirable to provide a binding which can be quickly and easily attached and detached even though the snowshoer's finger dexterity may be limited due to coldness or handgear.
Accordingly, there is a need for an improved snowshoe which addresses the limitations and challenges facing snowshoe designers.